Difference between revisions of "AVR Drivers"

Of course you will need a flashlight driver circuit board first. The stock driver in some flashlights already has an Atmel driver on board. There are also several NANJG drivers available that include an Atmel TINY13A chip that can be programmed. ATtiyny13A can also be locked down (low fuse higher than 0x7F) so they can't be changed easily, but so far none seem to be. However, some variants of NANJG drivers use a PIC chip that can not be programmed with AVR tools, as well as Kaidomain driver doesn't use ATtiny13A. See [[Popular drivers]] to see some of the drivers people have been using. Most of these use current regulators to limit the current delivered to the LED while the Atmel chip itself turns the power on and off very quickly, leaving it on for full power, or flashing on and off quickly to simulate a lower mode. As the percentage of off time increases, the light gets dimmer. By setting the on-off cycles to a high frequency, the eye just sees this as a lower mode even when the LED is barely lit. This is called Pulse Width Modulation (PWM). By slowing the flashing more, you get a visible strobe mode or SOS modes. So essentially the Atmel chip is just a computer-controlled on-off switch.

The Atmel ATtiny13A has an 8-bit processor with 1 kb of flash memory, 64 bits of RAM, and 64 bits of EEPROM that can be written several thousand times. There are also settings called "fuses" which can be set or cleared.